1. Field of the Invention
The present invention is related generally to biocompatible coatings. More specifically, the present invention is related to the modification of medical device surfaces for the application of biocompatible coatings.
2. Background Art
Implantable medical devices including, pacemakers, defibrillators, neurostimulators, venous introducers, and catheters are devices that are well known to help improve health and sustain life. However despite the significant benefits that implantable medical devices provide, their use could lead to thrombosis, a serious medical problem that could result in death. Thrombosis is the formation of a blood clot within a blood vessel that obstructs blood flow leading to possible stroke, heart attack, organ failure and death.
Medical device related thrombosis initially occurs as a result of an interaction between blood and the surface of the medical device when they are in contact with each other. Once blood is in contact with the medical device, blood platelets and other blood constituents begin to coagulate and clot on the device surface. Blood clotting is known to occur on both metallic and polymeric materials, materials which are used to manufacture medical devices.
After the formation of the blood clots have occurred on the device surface, the clots could break off from the surface, travel through the blood stream, become lodged in a blood vessel and obstruct blood flow. Thrombosis is an especially major problem for permanently implanted devices that are in continuous blood contact.
A great deal of work has been done to develop coatings which reduce cell adhesion and activation. These coatings, referred to as biomimetic coatings, can inhibit the formation of blood clots and therefore reduce the possibility of thrombosis from occurring.
One such family of biomimetic coatings are surfactants described by Marchant et al. in U.S. Pat. Nos. 6,759,388 and 7,276,474 and U.S. patent application publications 20080247988 and 20080262614, which are herein incorporated by reference.
These coatings provide good blood clot inhibition. However, adhesion of these coatings to many medical device surfaces, particularly those device surfaces that are in constant contact with blood, could benefit from improved coating adhesion. In particular, adhesion to polymeric surfaces specifically made of silicone, polyurethane and polyether block amide (PEBA) materials are not ideal.
An objective of the present invention, therefore, is to provide a means of modifying the surface of the medical device to improve the adhesion of the biomimetic polymer coatings over a wider range of medical device surfaces.